Suturing is a medical procedure for the joining of biological tissues with needle and suture thread or by other means (adhesive) thereby binding tissue together to promote healing. For our purposes suturing is a process where a needle threaded with suture material is used to close an external or internal surgical opening or wound, join together two blood vessels or any two types of biological tissues with one or more stitches that pass through the bordering tissue near its edges.
Suturing, and in particular microsuturing requires great dexterity for manipulating the tissues, the needle and in tying the knot. The suturing and knot-tying procedures require the use of both hands. While suturing may be performed with a straight needle, this practice would be difficult in the microenvironment with current technology. Typically the inner surface of the tissue bordering the opening is not accessible necessitating the use of a curved needle handled with forceps and a needle holder or driver. The threaded needle is initially made to penetrate (inward) the tissue on one side of the opening and is then guided to penetrate (outward) tissue on the other side of the opening. Care must be exercised to insure that the out-of-sight needle does not undesirably penetrate nearby hidden tissue or structures. After reemergence of the needle and its attached thread, the needle may be separated from the thread and the two ends of the thread may be tied together to form a surgical no-slip knot. The reliability of the no-slip knot depends, to a large extent, on the physical properties of the suture material. It is important to keep the two tissues joined until the healing process is complete.
When multiple stitches are required to close an opening, the suturing process may be repeated providing a sequence of single individually tied stitches. This type of suture is known as an interrupted suture in that each stitch is individually knotted. Alternatively, when multiple stitches are necessary, the threaded needle may be repeatedly inserted and retrieved from the tissue and only then tied to form a single knot. This type of suture is known as continuous or “running” closure. For the same number of stitches, continuous closure may be performed more quickly than interrupted suturing. For continuous closure suturing, however, the failure of a single one of the constituent sutures or of the knot can result in the failure of the entire suture line. In addition, continuous closure does not permit individual adjustment of the tension provided by each of the suture stitches.
The tissue penetrations resulting from the suturing procedure when performed on blood vessels, ducts or other lumens, conveying blood or other bodily fluids may result in undesirable leakage. In some cases, mechanical pressure must be applied to the puncture site, for a sufficient period of time, until hemostasis occurs.
The material used for suture thread has evolved over the millennia. Suture materials may be classified as absorbable vs. non-absorbable and braided vs. non-braided (monofilament). Suture thread must simultaneously meet sometimes opposing stringent physical and biocompatibility requirements necessitating a compromise selection. For example, the surface of the suture material should have a sufficiently high coefficient of friction (i.e., rough surface) to hold a no-slip knot while simultaneously minimizing the potential for infectious agent adhesion (i.e., smooth surface).
The inventors have identified the need to develop a procedure and apparatus that can be used to perform suturing with a single hand, relax some of the requirements placed on the suture thread related to knot reliability, and simultaneously provide the benefits of interrupted suture and continuous closure suturing that can be used in both macro, microsurgical and endoscopic situations. In addition, in some procedures or situations, a need exists to facilitate the rapid sealing of the suture puncture site thereby minimizing leakage of bodily fluids.